Electromechanical driving system for time-piece gearing



G. VOSSELER Aug. 10, 1965 ELECTROMEGHANICAL DRIVING SYSTEM FORTIME-PIECE GEARING Filed Dec. 21, 1962 FIG.

MECHANICAL FEEDBACK United States Patent 3,209,270 ELECTROMECHANICALDRIVING SYSTEM FOR TIME-PIECE GEARING Gerhard Vosseler, Rosieres,Switzerland (Steinentorstrasse 25, Basel, Switzerland) Filed Dec. 21,1962, Ser. No. 246,563 Claims priority, applicatirlizi/ Sgvitzerland,Jan. 5, 1962,

2 Claims. (Cl. Sill-8.5)

Various types of time-pieces are known wherein the time base isconstituted by an oscillator the oscillations of which are maintainedthrough electronic means. The oscillators control an arrangement fordriving a gear constituted for instance by a catch or by a synchronousmotor.

When the oscillator operates under comparatively low frequencyconditions, it is possible to resort to a purely mechanical drivingsustem such as a catch-actuated mechanism and this is in particular thecase for certain time-pieces where the time base is constituted by atuning fork oscillating at a frequency of 100 to 200 cycles and which isprovided with a catch cooperating with a finely toothed ratchet wheel.

In contradistinction, when the oscillation reaches higher frequencyconditions as is in particular the case with quartz oscillators, it isnecessary to resort either to electrical driving means or to frequencydividers. The latter are however of a comparatively intricate structureand their bulk is so large that they cannot be used in wrist watches.

My invention has for its object a mechanical driving system for atime-piece gear under the action of an oscillator defining the time baseof said time-piece and operating at a comparatively high frequency.

According to my invention, I resort to an oscillating member controlledby said oscillator and carrying a rod the end of which engages theperiphery of a driving gear under a pressure and along a direction suchthat, when said member oscillates at its resonance frequency, the rodundulates in response to the oscillations and urges the gear forwardsand drives it rotationally.

I have illustrated, by way of example, in the accompanying drawings, apreferred embodiment of my invention. Inthe drawings:

FIG. 1 is a wiring diagram illustrating the operation of a quartzoscillator and FIG. 2 is a modification of the embodiment of FIG. 1.

FIG. 3 is a perspective view of the mechanical parts of an embodiment ofthe invention.

The oscillator illustrated in FIG. 1 forms a time base for a time piece.It includes two quartz crystals 1 and 2, a transistor 3 and a supply ofelectrical energy 4. The quartz crystal 1 acts as the collecting memberand the signal produced by its relases the transistor 3 which thenallows current to pass through the second quartz crystal 2. The latterbegins vibrating and transmits its vibrations to the quartz crystal 1through as a mechanical feedback and also acts as a driving member ashereinafter explained. The feedback between the two quartz crystalscannot be obtained in a favorable manner unless the transmission of themechanical vibrations is undisturbed and if the two quartz crystals aredisposed sufiiciently near one another then maximum efficiency isobtained within the range of resonance frequencies of the quartzcrystals.

In the modification illustrated in FIG. 2, electric coupling between thetwo quartz crystals is obtained through the agency of a smalltransformer 4a which allows a certain reduction in the frequency ofoscillation of one of quartz crystals with reference to the other.According to further modifications which are not illustrated, it

3,200,270 Patented Aug. 10, 1965 is, of course, possible to resort toother types of oscillators.

The driving system includes a fine rod 5 (FIG. 3) glued by means of adrop of shellac to a strap 6 secured 5 to the driving quartz 2 which is,in its turn, fitted inside a support 7. The end 8 of the rod is appliedunder a pressure of a predetermined value and along a predetermineddirection against the smooth periphery of the driving ratchet wheel 9forming the first gear of the gearing of the time-piece. When theoscillator reaches its resonance frequency, the quartz 2 vibrates anddrives the rod 5 of which the end has imparted thereto a correspondingaxial shifting the frequency of which may range for instance between 1kilocycle and 1 megacycle. The presusre exerted on the rod and theangular setting thereof with reference to the ratchet wheel are suitablyselected so that the end of the rod may urge forwardly the ratchet wheelwhich starts revolving.

Experience has shown that the operation of such an arrangement isextremely uniform by reason of its lack of sensitivity in the presenceof any modification in the position of the watch, while the wear of therod is practically zero since the rod does not rub and acts merely onthe wheel through a series of short axial shocks of a reducedsensitivity. Furthermore, the structure is particularly simple and itsexecution is cheap since it requires no winding and no magnet as in thecase of corresponding electrical arrangements, nor does it require anyspring as in the case of all known mechanical arrangements. Lastly, itallows transforming directly through simple mechanical means,oscillating movements of a comparatively high frequency ranging between1 kylocycle and 1 megacycle or thereabouts.

Obviously, my invention is not limited to the arrangements described andillustrated and, in particular, the rod may be fitted on an oscillatingelement which is different from a quartz crystal, while the oscillatorsmay also be of a different type.

What I claim is:

1. Apparatus for driving a timepiece having a drive ratchet wheel saidapparatus comprising, an electromechanical oscillator comprising atleast one crystal for establishing a time base, a pawl comprising onundulatable thin rod having a free end and an opposite end portionfastened to said crystal driven undulatingly by said crystal to a bentcondition and an extended condition, said free end being disposed toengage said drive ratchet wheel on the periphery thereof and drive saidratchet wheel by undulations of said thin rod and subsequent extensionsthereof.

2. Apparatus according to claim 1, in which said thin rod is dimensionedin length and thickness to oscillate at a lower harmonic of thefrequency of said crystal oscillator and the amplitude of theundulations of said thin rod have a greater amplitude than themechanical vibrations of said crystal.

References Cited by the Examiner UNITED STATESPATENTS 1,693,806 12/28Cady 310-8.1 1,827,690 10/31 Rittenhouse 310-29 X 1,912,213 5/33Nicolson 310--8.2 1,995,270 3/35 Wallace 310-8.6 2,001,132 5/35 Hansell310-86 2,770,742 11/56 Fuchs 310-21 2,895,095 7/59 Guyton. 2,921,2521/60 Schiavone 310-81 2,985,777 5/61 Merchant 310-21 ORIS L. RADER,Primary Examiner. MILTON O. HIRSHFIELD, Examiner.

1. APPARATUS FOR DRIVING A TIMEPIECE HAVING A DRIVE RATCHET WHEEL SAIDAPPARATUS COMPRISING, AN ELECTROMECHANICAL OSCILLATOR COMPRISING ATLEAST ONE CRYSTAL FOR ESTABLISHING A TIME BASE, A PAWL COMPRISING ONUNDULATABLE THIN ROD HAVING A FREE END AND AN OPPOSITE END PORTIONFASTENED TO SAID CRYSTAL DRIVEN UNDULATINGLY BY SAID CRYSTAL TO A BENTCONDITION AND AN EXTENDED CONDITION, SAID FREE END BEING DISPOSED TOENGAGE SAID DRIVE RATCHET WHEEL ON THE PERIPHERY THEREOF AND DRIVE SAIDRATCHET WHEEL BY UNDULATIONS OF SAID THIN ROD AND SUBSEQUENT EXTENSIONSTHEREOF.